GEOGRAPHICAL DISTRIBUTION 333 



in Hypocrea there are 102 species for Europe and North 

 America, against 54 for all other localities. This will be 

 sufficient to show that the majority are in favour of a temperate 

 climate. 



Taking the Hothideaceae and Microthyriaceae together, the 

 number of species would be about 650. A large number of 

 the species appear as shining black dots or patches on living 

 or fading leaves, and especially the leaves of forest trees. 

 Some, of course, are erumpent on twigs. We have only been 

 able to trace 116 European species, or about one-sixth of the 

 whole, and there are certainly not so many more in the United 

 States, so that two-thirds of the total number will be tropical 

 or subtropical. 



Of the 7500 species of the Sphaeriaceae we cannot 

 attempt an analysis. Ellis gives 1680 North American 

 species, which is two-ninths of the whole, and many of these 

 are European also. Some of the species are cosmopolitan, 

 such as Daldinia concentrica ; and some, such as Xylaria 

 polymorphs and Xylaria hypoxylon, are found almost every- 

 where, even in the tropics. Xylaria and Hypoxylon have their 

 representatives all over the world, arnid heat or cold, but 

 with an evident preference for the former. In Cuba we find 

 20 species of Xylaria and 30 of Hypoxylon, in Ceylon 

 nearly the same number of both ; but of the simple scattered 

 Sphaeriaceae the number of species is very small, — probably 

 only a very few collectors would observe them or hunt for 

 them, and they require looking after, — yet there is no reason 

 why they should not be as common in the north of Africa or 

 South America as in the United States or the south of Europe. 

 The 300 species of Lophiostomaceae might practically be united 

 with the above, as they follow the same distribution. Of 

 these 170 are European, and only about 20 subtropical. 

 Another small group consists of the Hysteriaceae, in which the 

 texture is that of Sphaeriaceae, but with the habit and com- 

 pact disc of the Discomycetes. The number of species is also 

 about 300, and some of these are widely distributed ; they are 

 capable of bearing a subtropical climate, although only about 

 84 occur outside of Europe and North America, and not more 

 than half of these are subtropical. 



